Does life exist on other planets beyond our Solarsystem

Does life exist on other planets beyond our Solarsystem? There is a high probability that life does exist on other planets than Earth.
But what do mean by 'life'? When we're talking about life we mean life as we know it: carbon based organic life forms that needs liquid water to exist.
So not all planets are capable of sustaining life. We know that already for quite some time, because in our Solarsytem Earth is the only planet of which we certain know that it sustains life. Mars could also have had life on it, but that isn't for sure. A planet has to meet certain conditions to be able to support life; the main condition is that the planet has to lie in the habitable zone. This is the region around a star in which life-supporting planets can exist; the boundaries are named the inner and outer edge of the habitable zone.
This means the habitable zone of a star requires certain conditions for a planet:
the star has to be a main sequence star (i.e. a star burning steadily light elements into heavy ones) the planet has to be solid to allow for a liquid-solid interface, this to enhance the exchange between molecules the planet has to be at the right distance from the star to allow for liquid water (temperature dependence) With the formula below (J. Schneider)¹ we can calculate the equilibrium temperature of a planet orbiting a certain star. A planet acquires, by heating, an equilibrium temperature Tp given by: ,Where A is the mean albedo (reflectance) of the planet surface at a distance a around a star with radius Rs and temperature Ts. On this page I will outline some things related to the question on top of this page.
The habitable zone (HZ) is the region around a star in which life-supporting planets can exist (Huang 1959,1960).

The habitable zone for Earth-like planets orbiting main sequence stars, is determined by water loss on the inner edge and by CO2 condensation, leading to runaway glaciation, on the outer edge. Planetary habitability is critically dependent on atmospheric CO2 and its control by the carbonate-silicate cycle. Conservative estimates for the boundaries of the Sun's (G type star) current HZ are 0.95 AU for the inner edge and 1.37 AU for the outer edge. The actual HZ width is probably greater, but is difficult to determine an exact value because of uncertainties regarding clouds which affect the planetary albedo. HZ widths around other stars in the spectral classification range of interest, F to M (~7200 to ~3000 Kelvin), are approximately the same if distances are expressed on a logarithmic scale (i.e. if you plot the distances from the inner and outer edges of the CHZs for different stars on a logarithmic axis, you will find that the widths of the CHZs for the different stars is about the same on this scale). If planets exist around other stars (they do) and if planetary spacing is logarithmic, as in our Solar System, the chances that one or more planets will be found within a star's HZ are fairly good.
The continuously habitable zone (CHZ) is the HZ that stays the HZ during the lifetime of the star. Because the star evolves the boundaries of the HZ will change slightly too, the CHZ will not change so the width of the CHZ will be smaller than the width of the HZ.
The width of the continuously habitable zone (CHZ) around a star depends on the time that a planet is required to remain habitable and on whether a planet that is initially frozen can be cold-started by a modest increase in stellar luminosity. CHZs are generally narrower than HZs because the boundaries of the CHZ migrate outward as a star ages. Despite this, the 4.6 Gyr CHZ around our own Sun extends from at least 0.95 to 1.15 AU and is probably considerably wider. CHZs around early K stars should be somewhat wider (in log distance) than around G stars because the K stars evolve more slowly. Equivalently, one could say that their CHZs are longer-lived. Since there are approximately three times as many K stars as G stars, this suggests that the majority of habitable planets may reside around K stars. Late K stars and M stars would have even wider CHZs, but the planets within them are susceptible to tidal damping and will probably rotate synchronously after a few billion years. F stars should have narrower CHZs than do G stars (on a log distance scale) because they evolve more rapidly. High ultraviolet flux are another potential problem for life around F stars. Stars earlier than ~F0 have main sequence lifetimes of less than 2 Gyr, so their planets are probably not suitable for evolving intelligent life. But 'simple life' could evolve here.